Gas burner



May l, 1934 A. B. CUNNINGHAM 1,955,857

GAS BURNER Filed Feb. 5. 1931 a burner which will J which is soconstructed that the flame is emitted Patented May l, 19,34

N'E OFFICE GAS BURNER Arthur B. Cunningham,

to Autogas poration of Delaware Application February 5, 1931, Serial No.

Chicago, Ill.; assigner Corporation, Chicago, Ill., a cor- 14 Claims.(Cl. 158-99) This invention relates to gas burners and has to doparticularly with burner structure of the character well adapted for usewith gas heaters, furnaces, and boilers for heating systems, and whereinthe gas flow to the burner may be controlled by thermostatic or handoperated means.

One of the objects of this invention is to provide a burner structure ofmaximum efficiency and universal application.

Another object of the invention is to provide a gas burner wherein thellame issuing therefrom is narrow in cross section and wherein secondaryair is supplied to each side of such llame to effect complete andeicient combustion of the gases.

Still another object of the invention is to provide a burner wherein anunbroken sheet of iiame, in contradistinction to a series of smallerflames issuing from separate ports, as in the multi-jet type, is emittedfrom the burner and wherein complete and efficient combustion iseiTected by the supply of a minimum amount of excess air to either sideof said flame.

A further object of the invention is to provide give an intense flameand laterally from the burner and in the form of a ring narrow in crosssection.

A still further object of the invention is to provide a unitary burnerhead wherein the gas is emitted laterally from a narrow slit-likedischarge orice and wherein the secondary air is directed into intimatecontact with the gases on either side of the llame thereby aiecting anexpeditious, complete, and efficient combustion of the gases, whichenables the burning of a large volume of gas in a minimum of time.

A still further object of the invention is to provide a unitary burnerstructure wherein a combustible mixture is discharged laterally in asheetlike ring narrow in cross section with a minimum of excesssecondary air supplied thru mea-ns which directs the same into intimatecontact with the sides of the flame.

Additional objects of the invention are to provide a unitary burnercapable of installation in any form of heating plant, domestic orotherwise; of low operating and maintenance costs, of an enduring natureand virtually noiseless in operation.

The various features of novelty which characterize the invention will bewell understood by reference to the following description of anillustrativeV embodiment of the invention shown by way of example in theaccompanying drawing.

Fig. 1 is a sectional view thru the burner assembly illustrating itsapplication to one type of combustion chamber.

Fig. 2 is a sectional view of a modified burner head and adjustablesupport therefor.

Fig. 3 is a broken View, with certain parts removed, illustratingdetails of the supporting means of Fig. 2.

The burner illustrated is particularly adapted for use with the burnerillustrated in the application of Ashur U. Wetherbee, Serial No.493,537, nled November 5, 1930. However, it is to be understood thatthis invention is not limited to that particular application, but thatit may be applied generally wherever gas heating is desired.

The burner illustrated in the aforesaid application comprises acombustion chamber composed of a base with super-imposed rings placedthereon and dening a combustion zone, into which the primary mixturewith an adequate, but not an excess amount of secondary air isintroduced and burned. The llame and products of combustion passing upthrough this combustion chamber heat the chamber to a high degree ofincandescence, which emits radiant heat. The present invention has to dowith means for properly proportioning and introducing the combustiblemixture to the zone of combustion, whereby large quantities of gas canbe completely and eilciently burned with consequent development oiintense heat.

Referring to the exemplary embodiment of the invention illustrated inFig. 1, the numeral 10 designates an assembly casing particularlydesigned to be readily installed in a conventional domestic heatingsystem or furnace and is of such size as to pass freely thru the ashpitdoor of such a heating system. This casing 10 is preferably made ofsheet metal and is provided with suitable legs 11 adjacent its front andrear ends. A casting 12, provided with suitable openings therein, isdetachably connected to the front end of the casing, while the rear endof the casing is closed by a casting 13 provided with a laterallyextending top portion 14 adapted to form a support for a refractorycylinder which may be of the type illustrated in the prior applicationabove mentioned. The laterally extending top portion is provided with anopening 15 and the base ring 16 is provided with an opening 17 ofsmaller diameter than the opening 15. By virtue of this arrangement aportion 18 of the bottom of the base ring overhangs the supportingstructure of the top extension and thereby protects such ex- 23 andopening tension and the casing from the intense heat developed withinthe burner.

Enclosed within the casing is a mixing tube 19 having a constriction inthe form of a Venturi throat and supported at its forward end by casting12 and at its rear end by a bracket 20 carried by the rear casting 13,the connection with the bracket being of a detachable character tofacilitate removal and replacement of the tube.

The rear end of the tube 19 is expanded to form the lower portion of theburner head and contributory to that end, openings 21 and 22 areprovided in the upper and lower walls respectively of the tube and saidopenings are preferably concentrically arranged. The concentric spacebetween the short tube 23, fitted into the opening 21, and the longertube 24, tted into the lower opening 22, constitutes a continuation ofthe tube 19, and the upper end of the tube 24 is ared outwardly as at 25to cooperate with the tube 23 to form therewith an opening 26 of narrowslit-like character thru which the primary mixture of gas and air isdischarged. Tubes 23 and 24 are preferably made of heat resistingmaterial and tube 24 carries a support 27 in the form of a spider whichsupports the cap 2S. This cap is preferably made of a refractorymaterial and its primary functions are to divert the secondary airdischarged thru tube 24 into proximity to the flame emitted from thedischarge slot 26 and to prevent excessive heating of the burner head. Aspud or nozzle 29 is conveniently mounted in the forward end of the tube19 for directingT the gas into said tube and an air shutter 30 forregulating the ow of air into the end of the tube 19 is adjustablymounted upon the spud for adjustment to and from the end of the tube toregulate the flow of primary air into the mixing tube. A door 31 havinga central offset portion pivotally mounted on a knife edge supportcarried by the casting 12 provides means for regulating the flow ofsecondary air to the burner.

In the operation of the device the gas discharged thru the inlet spud 29aspirates primary air as it passes into the throat of the mixing tube 19and the shutter 39 is adjusted so that the admixture of air and gas inthe tube forms therein a combustible mixture which flows between thetubes 23 and 24 and out thru the discharge opening 26 where it isignited by a suitable means, such as a pilot light, not shown, and burnsin the form of a continuous flame, in the present instance, a thin sheetor ring of flame. This discharge of the combustible mixture coupled witha slight suction in the rcbox, induces a flow of secondary air, thru thedoor 31, which divides into two flow paths, one of which is thru thetube 24 while the other is around the tube 23 and thru the opening 17 inthe base ring 16. The secondary air passing up thru the tube 24 contactswith the cap 28 is preheated and diverted outwardly through opening 32into intimate contact with the upper side of the flame, while the airpassing thru the opening 33 defined by tube 17 in the base ring 16 ispreheated by contact with the portion 18 and directed to the lower sideof the iame. The secondary air inlet openings are proportioned so that aminimum of excess air is supplied to complete combustion. In practice,it has been found that for efiicient operation under normal conditions,the areas of the primary discharge outlet 26 and the secondary airoutlets 32, 33, respectively bear a certain relation to each other andthis relationship is substantially in the ratio of 1:2110, that is, thesecondary air opening 32 has an area twice that of the primary mixtureoutlet opening 26, while the other secondary air opening 33 is ten timesthat of the primary mixture opening 26. These ratios have been foundsatisfactory on standard gas pressure of substantially two to threeinches of water, and it is to be understood that other ratios may beworked out for different conditions of operation.

With the secondary air and gas proportioned as described, an intenseheat is produced, while at the same time a large volume of gas may becompletely and efliciently burned, because the ame is projected in theform of a thin sheet and the secondary air is supplied to each side ofthe flame in sufficient, but not excessive, quantities to supportcomplete and eiiicient combustion of the gases.

Rapidity of combustion depends upon securing an intimate commingling ofthe combustible gas with the secondary air. This commingling is largelydue to the diffusion of the air and combustible gas to secure actualContact between each molecule of the combustible gas and the necessarymolecules of oxygen of the air. The thin sheet of flame accelerates theadmixing of the molecules since there is a smaller initial distancebetween the molecules at the center of the flame and the requiredmolecules of oxygen in the secondary air than would ordinarily be thecase in a flame of the jet type.

The tubes 23 and 24 are securely tted into the openings 21 and 22,respectively, in the tube 19 as by sweating or welding or they may bethreaded therein, as in Fig. 2, to prevent the escape of the primarymixture as it flows through the tube to the combustion zone. Since thetubes, and particularly the portions adjacent the outlet end, aresubject to high temperatures they may be made entirely of non-corrosiveheat resisting material such, for example, as ascaloy metal, or ifdesired` they may be made in two or more parts as in Fig. 2, with thelower parts 34 and 35 sccured in the openings in the tube 19 and thetips or extensions 36 and 37, of non-corrosive and heat resistingmaterial welded or otherwise secured in place on the 1 wer parts. Anon-cerrosive heat resisting material is preferable to maintain thecharacteristics ef the burner by preventing corrosion of the partsduring nonuse and the warping and burning away of the parts duringconstant use.

In Fig. 2, adjustable supporting means for the burner head is shown, inwhich the burner head may be adjusted both vertically and axially toproperly position the same relative to the base 16. The mixing tube 19is preferably provided, on opposite sides, with tapped lugs 38 intowhich the screws or bolts 39 are threaded and the extension 14 has apair of spaced key-hole slots 40 for the reception of the screws 39. Toinsert the mixing tube and burner head the Shanks of the screws arepassed into the slots 40 and the tube lowered until the heads of thescrews rest in the enlarged portion of the slots, likewise. to removethe burner head the tube is raised and the screws 39 passed out of theslots. The base 16 may be either removed or slightly raised tofacilitate the insertion or removal operations. By collectivelyadjusting the screws 39 the burner may be raised or lowered to correctlyposition the discharge outlet 26 with respect to the interior end of thebase 16, and by individually adjusting the screws 19, the burner headmay be tilted laterally to bring the discharge outlet 26 into position,preferably parallel with the inner edge of the opening 17, butsufficiently above the interior end of the base 16, so that the flameemitted from the discharge outlet 26 will pass into the bowl of the basewithout impinging against the wallsk of opening 17.

From the foregoing, it will be seen that with a burner arrangement ofthe type disclosed, a high degree of efficiency is obtained because ofthe complete and efficient combustion of the gases and a large volume ofgas may be burned withr a minimum of excess air, since the flame isnarrow in cross-section and the secondary air is supplied to cach sideof the flame thereby accelerating complete combustion of the combustibleconstituents of the gas. This type of burner is well adapted to on andolf control since it is practically noiseless in operation and may bestarted without popping or explosions and discontinued or stoppedwithout puffing. Various changes in details of construction may be madewithout departing from the spirit of the invention.

What I claim is:

l. A burner assembly unit for insertion in the ash pit door of afurnace, comprising a casing closed at each end and provided with anopening in its top wall adjacent one end, a mixing tube provided with aburner head terminating in a flame discharge orifice, and means foradjustably and removably supporting said tube in said casing with saiddischarge orifice above the openingin said top wall.

2, A burner assembly unit for insertion in the ash pit door of afurnace, comprising a casing closed at each end and provided with anopening in its top wall adjacent one end, a mixing tube provided with aburner head terminating in a flame discharge orifice, and readilydetachable means for removably supporting said tube in said casing withsaid discharge orifice above the opening in said top wall.

3. An assembly unit for insertion in the ash pit door of a furnace,comprising a casing having the top wall thereof cut away adjacent oneend, an end casting for closing the latter end of the casing andprovided with an extension covering the opening in said top wall, therebeing an opening in said extension, a casting for closing the other endof said casing and provided with an aperture, a burner head providedwith a mixing tube mounted in said aperture, and means carried by thefirst mentioned end casting for detachably and adjustably supporting theburner head with the flame discharge orifice above the top extension.

4. A gas burner including a base having a restricted opening in one endthereof, a burner head comprising tubular elements positioned in saidopening for discharging a combustible mixture outwardly of the base, theend wall of the base adjacent the discharge orifice being concave todirect the flame laterally and outwardly of the base, and supportingmeans for said burner head overlain and protected from said flame bysaid base.

5. A gas burner including a base having an opening in the end of lessdiameter than the interior diameter of the base, and the interior wallof the base converging towards said opening to form a flame directingsurface, and means for supplying a combustible mixture to said baseadjacent said curved wall whereby the flame is directed laterally andoutwardly of said base and including an annular passage directedimmediately above and substantially parallel to said directing surface.l

6. A gas burner including a refractory base having side and end wallsand there being an opening in the end wall of less diameter than theinterior diameter of the base, and the end wall converging towards saidopening to form a flame directing surface, and a burner structurecomprising concentrically arranged tubes, defining a primary combustiblemixture duct and the inner tube being flared outwardly into proximity tothe outer tube to define with said tube a discharge orifice fordirecting the flame outwardly and along the flame directing surface, andmeans for directing a secondary supporter of combustion to each side ofthe flame whereby the flame is prevented from contacting directly withthe directing surface.

'7. A gas burner including a base having an opening in the end thereofwith the interior wall of the base converging towards said opening to'form a flame directing surface, and a burner structure comprisingconcentrically arranged tubes defining a primary combustible mixtureduct with the inner tube flared outwardly into proximity to the outertube to define with said tube an annular discharge orifice for directingthe flame outwardly and along the fiame directing surface, a deflectorpositioned above the outlet of the inner of said tubes, the outer ofsaid tubes of smaller diameter than the opening in the end of the basewhereby the secondary air in passing up and around the larger tubecontacts with the undei-side of the flame and cushions the same againstcontact with the directing surface while the air discharging from theinner tube contacts with the defiector and is deflected into Contactwith the upper surface of the flame.

8. A gas burner including a base ring having the lower end thereoftapered inwardly to define an opening, a burner head includingconcentrically arranged tubes projecting through said opening, saidouter tube defining with said opening a secondary air inlet and saidinner tube defining a secondary air inlet, said inner tube flaringoutwardly into proximity to the end of the outer tube to dene therewitha primary gas and air mixture discharge nozzle for directing the fiameoutwardly along the tapered end wall, and a refractory defiectorsuperimposed above the inner tube for directing the secondary airemitting therefrom into Contact with the flame, the arrangement beingsuch that the secondary air passing through the annular opening formedby the outer tube contacts with and shields the flame from the taperedwall of the base, while the secondary air emitting from the inner tubeis directed against the upper surface of the flame whereby the flame issurrounded on each side by secondary air and complete and efficientcombustion is obtained.

9. A burner comprising a flame-directing base, members defining anannular narrow discharge outlet through which a primary combustiblemixture may be discharged in the form of a thin sheet paralleling saidbase and means for supplying a supporter of combustion to each side ofsaid sheet in the ratio of substantially five times the volume on theside next said base as compared to the volume on the other side thereof.

l0. A burner comprising in combination a base having an openingtherethrough, inner and outer co-axial tubular members spaced apart toprovide a gas passage therebetween and co-axially located in saidopening to provide a secondary air inlet between the outer member andthe inner edge of the opening, the areas of gas discharge and secondaryair inlet openings being substantially in the ratio of one to ten,respectively.

11. A burner comprising in combination a base having a circular openingtherein, inner and outer tubular walls spaced apart to form a passagetherebetween, the inner wall flared outwardly and coacting with the topof the outer wall to form therewith a narrow slit like discharge outletfor directing a combustible mixture in the form a ihinsheet,y outwardlytherefrom, said walls positioned co-axially of the circular opening todefine an annular seconda-ry air inlet between the outer wall and theedge of the circular opening, and a deiicctor coacting with the flaredportion of the inner wall to form therewith another secondary air inletopening, said secondary inlet openings directing the air to either sideof the gas discharge openings and the areas of gas and secondary airopenings being substantially in the ratio of one for the gas opening totwo for one of the air openings and ten for the other of the airopenings.

12. A burner unit comprising a casing adapted to extend outwardlythrough the door of a furnace and having its rear end closed and anopening in its top wall adjacent said closed end, a primary air and gasmixing tube provided with a discharge outlet at its rear end, meansadjacent the exterior end of the casing for supporting the forward endof said tube and means for adjustably supporting the other end of saidtube with the discharge outlet thereof coordinated with the opening inthe top wall of the casing.

13. A conversion burner unit comprising a conduit adapted to extendoutwardly through the door of a furnace to provide a secondary air inletto said furnace, said casing having an opening in its top wall adjacentthe rear end thereof, a primary air and gas mixing tube in said casingand supported adjacent the outward end thereof and means for removablysuspending the rear end of said tube from the top wall of said casing.

14. A burner apparatus comprising an air supply conduit for a furnaceand adapted to extend outwardly therefrom and provided with an openingin its top wall adjacent the rear end thereof, a primary air and gasmixture tube provided with a discharge opening at its rear end, saidtube disposed in said casing, and means for removably and adjustablysupporting said tube from the top wall cf the conduit with the dischargeopening thereof in proper relation to the opening in the top wall ofsaid conduit.

ARTHUR B. CUNNNGHAM.

